Tape measure with tape blade including end protective film

ABSTRACT

A tape measure including an elongate tape blade is shown. The tape measure includes a relatively short protective polymer film coupled to an end of the tape blade adjacent to the hook end of the tape blade.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

The present application is a continuation of International PatentApplication No. PCT/US2020/030719, filed Apr. 30, 2020, which claims thebenefit of and priority to U.S. Provisional Application No. 62/843,041,filed on May 3, 2019, which are incorporated herein by reference intheir entireties.

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of tools. Thepresent invention relates specifically to a tape measure, measuringtape, retractable rule, etc., that includes a relatively shortreinforcing polymer film coupled to the end of the tape blade adjacentthe outer hook end of the tape blade.

Tape measures are measurement tools used for a variety of measurementapplications, including in the building and construction trades. Sometape measures include a graduated, marked blade wound on a reel and alsoinclude a retraction system for automatically retracting the blade ontothe reel. In some typical tape measure designs, the retraction system isdriven by a coil or spiral spring that is tensioned, storing energy asthe tape is extended and that releases energy to spin the reel, windingthe blade back onto the reel.

SUMMARY OF THE INVENTION

One embodiment of the invention relates to a tape measure including areinforced tape blade. The tape blade includes a metal core, a firstcoating layer on an upper surface of the metal core, a second coatinglayer on the lower surface of the metal core. A hook assembly is coupledto a first end of the tape blade. The tape measure includes a protectivepolymer film adhered to an outer surface of least one of the firstcoating layer and the second coating layer adjacent the hook assemblysuch that a portion of the hook assembly extends over the protectivefilm in the lengthwise direction of the tape blade. A longitudinallength of the protective film is less than 10 inches and specifically is4 to 8 inches. In various embodiments an adhesive layer binds theprotective film to the adjacent coating layer. In various embodiments, apeel strength of the protective film to the adjacent coating layer isgreater than 9 lbs.

Another embodiment of the invention relates to a tape measure includinga housing, a reel rotatably mounted within the housing and an elongateblade wound around the reel. The elongate blade has an inner end coupledto the reel and an outer end extending out of the housing. The tapemeasure includes a hook assembly coupled to the outer end of theelongate blade and a retraction system coupled to the reel. Theretraction system drives rewinding of the elongate blade on to the reel.The elongate blade includes an elongate metal core having an uppersurface and a lower surface, and the upper surface includes a concavecurved section and the lower surface includes a convex curved section.The elongate blade includes an upper polymer coating layer covering atleast a portion of the upper surface of the elongate metal core and alower polymer coating layer covering at least a portion of the lowersurface of the elongate metal core. The elongate blade includes an inklayer forming a series of measurement markings and is located betweenthe upper surface of the elongate metal core and the upper polymercoating layer. The elongate blade includes a protective film coupled viaan adhesive to an outer surface of the lower polymer coating layeradjacent to the outer end of the elongate blade, and the protective filmhas a length that is less than 20% of a total length of the elongateblade.

Another embodiment of the invention relates to a tape measure includinga housing and a reel rotatably mounted within the housing. The tapemeasure includes an elongate blade wound around the reel, and theelongate blade has an inner end coupled to the reel and an outer end.The tape measure includes a hook assembly coupled to the outer end ofthe elongate blade and a retraction system coupled to the reel. Theretraction system drives rewinding of the elongate blade on to the reel.The elongate blade includes an elongate metal core having an uppersurface and a lower surface. The upper surface includes a concave curvedsection and the lower surface includes a convex curved section. Theelongate blade includes a protective film coupled via an adhesive to theelongate metal core. The protective film has a length less than a totallength of the elongate blade, and a peel strength between the protectivefilm and an adjacent surface of the elongate blade is greater than 9lbs.

Another embodiment of the invention relates to a tape measure includinga housing and a reel rotatably mounted within the housing. The tapemeasure includes an elongate blade wound around the reel, and theelongate blade has an inner end coupled to the reel and an outer end.The tape measure includes a hook assembly coupled to the outer end ofthe elongate blade and a retraction system coupled to the reel. Theretraction system drives rewinding of the elongate blade on to the reel.The elongate blade includes an elongate metal core having an uppersurface and a lower surface. The upper surface includes a concave curvedsection and the lower surface includes a convex curved section. Theelongate tape blade includes an upper nylon coating layer covering atleast a portion of the upper surface of the elongate metal core and alower nylon coating layer covering at least a portion of the lowersurface of the elongate metal core. The elongate blade includes an inklayer forming a series of measurement markings and is located betweenthe upper surface of the elongate metal core and the upper nylon layer.The elongate blade includes a pressure-sensitive adhesive layer coupledto at least one of an outer surface of the upper nylon coating layer andan outer surface of the lower nylon coating layer. The elongate bladeincludes a protective film coupled to the pressure-sensitive adhesivelayer adjacent to the outer end of the elongate blade.

Additional features and advantages will be set forth in the detaileddescription which follows, and, in part, will be readily apparent tothose skilled in the art from the description or recognized bypracticing the embodiments as described in the written description andclaims hereof, as well as the appended drawings. It is to be understoodthat both the foregoing general description and the following detaileddescription are exemplary.

The accompanying drawings are included to provide further understandingand are incorporated in and constitute a part of this specification. Thedrawings illustrate one or more embodiments, and together with thedescription serve to explain principles and operation of the variousembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side perspective view of a tape measure, according toan exemplary embodiment.

FIG. 2 is a left side perspective view of the tape measure of FIG. 1with a portion of the tape measure housing removed, according to anexemplary embodiment.

FIG. 3 is a cross-sectional view of the hook end of a tape blade of thetape measure of FIG. 1 showing a tape blade film located on the bottomof the tape blade, according to an exemplary embodiment.

FIG. 4 is a top view of the tape blade film of FIG. 3 , according to anexemplary embodiment.

FIG. 5 is a perspective view of the tape blade film of FIG. 4 located ona roll of adhesive protective film, according to an exemplaryembodiment.

FIG. 6 is a cross-sectional view showing the tape blade film of FIG. 5located on the roll of release liner, according to an exemplaryembodiment.

FIG. 7 is a cross-sectional view of the hook end of a tape blade of thetape measure of FIG. 1 showing a tape blade film located on top of thetape blade, according to an exemplary embodiment.

FIGS. 8 and 9 illustrate aspects of a test procedure for measuring thepeel strength of various tape measures with tape blade film prototypesdiscussed herein as well as the films/coatings of commercially availabletape measures for comparison.

FIG. 10 shows tensile strength and elongation at break for materials fora tape blade film, according to exemplary embodiment.

FIG. 11 shows cross-sectional images of the tape blade of CommerciallyAvailable Prior Art 1.

FIG. 12 shows cross-sectional images of the tape blade of CommerciallyAvailable Prior Art 2.

DETAILED DESCRIPTION

Referring generally to the figures, various embodiments of a tapemeasure are shown. Various embodiments of the tape measure discussedherein include an outer polymer film layer coupled to a relatively shortlength of the tape measure blade located adjacent to the hook end of thetape measure blade. Applicant has found that by reinforcing a relativelyshort length of tape blade adjacent the hook, the tape blade will bemore resistant to wear, damage, cracking, etc. than tape blades withoutsuch reinforcement, while at the same time decreasing total tape coildiameter by limiting the reinforcing film to only a short section of thetape blade. Further, in some embodiments, Applicant has found that aprotective film having relatively high stiffness, further protects thetape blade from whipping during tape blade retraction.

In addition, in various embodiments, Applicant has developed a tapemeasure blade with an adhered, short, hook-end protective film, with avery high peel strength or adherence to the adjacent layer of the tapeblade. Through Applicant's testing, Applicant determined that a filmapplied to a short length of the tape blade may be subject todelamination during extend/retract cycles. Therefore, as discussed invarious embodiments herein, Applicant's designs include very high levelsof peel strength not believed present in commercially available tapemeasures.

In addition, Applicant has determined that the short, hook-endprotective film discussed herein help to allow for fast retraction time(0.6-1 sec from 8′) as stiffness of the tape blade is increased by afilm that helps resist whipping of tape blade upwards at faster speeds.In addition, Applicant has determined that the short, hook-endprotective film discussed herein increases the fatigue life of the bladeeven when whipping does occur. In addition, Applicant has determinedthat the short, hook-end protective film discussed herein holds theblade together longer even if tape cracks film, which prevents it fromhanging up on housing's components during retraction.

As noted below, in a specific embodiment, the short, hook-end protectivefilm discussed herein is located on the bottom surface of the tapeblade. In such embodiments, Applicant has determined that this placementhas better performance in cold weather during tape whip.

Referring to FIG. 1 and FIG. 2 , a tape measure, such as tape measure10, is shown according to an exemplary embodiment. Tape measure 10includes a tape blade, shown as coilable tape blade 14, and a housing18. In general, tape blade 14 is an elongate strip of material includinga plurality of graduated measurement markings, and in specificembodiments, tape blade 14 is an elongate strip of metal material (e.g.,steel material) that includes an outermost end coupled to a hookassembly, shown as hook assembly 26. In one embodiment, hook assembly 26includes one or more magnets to facilitate coupling of hook assembly 26to a workpiece during measurement. As will be discussed in more detailbelow, tape blade 14 may include various coatings and layers (e.g.,polymer coating layers, films, etc.) to help protect tape blade 14and/or the graduated markings of the blade from wear, breakage,whipping, etc., particularly during tape blade retraction. In oneembodiment, the first layer around steel is the paint, on which themeasuring scale is printed, and then the polymer or lacquer coating, onwhich the PET film is pasted.

As shown in FIG. 1 , a variable-length extended segment 22 of the tapeblade 14 is retractable and extendable from the housing 18. Hookassembly 26 is fixedly coupled to an outer end portion 30 of tape blade14. In various embodiments, tape blade 18 has a maximum length that maybe extended from the housing of between 10 ft. and 50 ft.

As shown in FIG. 2 , an inner end of tape blade 14 is coupled to a reel34, and the non-extended portion of tape blade 14 is wound onto reel 34,which is surrounded by housing 18. Reel 34 is rotatably disposed aboutan axis 38 of tape measure 10, and a retraction system or mechanism 42is coupled to reel 34 and configured to drive reel 34 about rotationaxis 38 which in turn provides powered retraction of tape blade 14. Ingeneral, retraction mechanism 42 drives rewinding of the elongate bladeon to tape reel 34. Retraction mechanism 42 may include one or moreelongated spiral springs that provide the retraction energy toretraction mechanism 42. In other embodiments, retraction mechanism 42includes other mechanisms such as one or more electric motors. A tapelock 46 is provided to selectively engage tape blade 14, which acts torestrain retraction mechanism 42 such that extended segment 22 of tapeblade 14 remains at a desired length.

Referring to FIG. 1 , housing 18 includes a first side wall 50, a secondside wall 54, and a peripheral wall 58 connecting first side wall 50 andsecond side wall 54. First side wall 50, second side wall 54, andperipheral wall 58 define an internal cavity 62, shown in FIG. 2 , inwhich reel 34 and retraction mechanism 42 are housed. Referring to FIG.1 , first side wall 50 and second side wall 54 have a substantiallycircular profile 66. In other embodiments, the side walls may berectangular, polygonal, or any other desired shape. Portions of thehousing 18 may be co-molded or separately formed of a resilientmaterial, such as a natural or synthetic rubber. In the illustratedconstruction, housing 18 is formed with housing bumpers 70 and a supportleg 74, which extends from a lower portion 78 of the peripheral wall 58.

A slot 82 is defined along a forward portion 86 of peripheral wall 58.Slot 82 provides an opening in the tape measure housing, which allowstape lock 46 to extend into housing 18. In addition, slot 82 provides alength sufficient to allow tape lock 46 to be moved relative to housing18 between locked and unlocked positions.

Below the slot 82, a tape blade opening in the housing, shown as tapeport 90, is provided in peripheral wall 58. Tape port 90 has an arcuateshape 94, corresponding to an arcuate cross-sectional profile of tapeblade 14. The tape port 90 allows for the retraction and extension oftape blade 14 to and from the internal cavity 62 defined within housing18.

As shown in FIGS. 1 and 2 , tape measure 10 includes a finger guardassembly 98. Finger guard assembly 98 includes a guard 102 and a guardsupport member 106. As shown in FIG. 1 , the portions of guard 102external to housing 18 are substantially U-shaped and extend downwardfrom housing 18. As shown in FIG. 2 , when tape blade 14 is in theretracted position, a rear surface of the hook assembly 26 abuts guard102.

Referring to FIGS. 3 and 4 , a hook end 110 of tape blade 14 is shownaccording to an exemplary embodiment. Tape blade 14 includes an elongatemetal core or inner layer 112 formed from a thin, elongate strip ofmetal material. In a specific embodiment, inner layer 112 is formed froma strip of steel material. In a specific embodiment, inner layer 112 hasa thickness, T1, between 0.09 mm and 0.2 mm, specifically, between 0.1mm and 0.18 mm (with up to a 25% thickness variation), and morespecifically of 0.11 mm to 0.13 mm. As will be understood inner layer112 may be formed in a concavo-convex configuration, which provides forthe curved shape of tape blade 14 shown in FIG. 1 . In such anarrangement, the upper surface of tape blade 14 and inner layer 112includes a concave curved section, and the lower surface of tape blade14 and inner layer 112 includes a convex curved section. Inner layer 112may be an alloyed spring steel, alloyed high strength steel, etc. In oneembodiment, the steel is of a hardness between 50-54 RHC (Rockwellhardness C). In another embodiment, the steel is of a hardness between45-60 RHC.

Tape blade 14 includes an upper coating layer 114 coupled to (e.g.,attached, bonded, glued, etc.) onto the concave upper surface of innermetal layer 112 and a lower coating layer 116 coupled to (e.g.,attached, bonded, glued, etc.) onto the convex lower surface of innermetal layer 112. In general, coating layers 114 and 116 are formed froma polymer material, and in a specific embodiment, are formed from anylon material. As shown, coating layer 114 has an upper surface 118that defines the uppermost surface of tape blade 14, and coating layer116 has a lower surface 120 that defines the lowermost surface of themajority of tape blade 14. Ink layers are located between coating layers114 and 116 forming measurement markings or indicia, and specificallythe ink layers are located on upper and lower surfaces of inner metallayer 112 between coating layers 114 and 116 respectively. In specificembodiments, the coating layers discussed herein are formed from a nylon12 material and/or a nylon 6/6 material. In various embodiments, coatinglayers 114 and 116 may be applied as a lacquer, laminate, nylonextrusion, film attached with adhesive, or a power/spray on coating.

In one embodiment, coating layers 114 and 116 may be applied over theentire length of inner layer 112. In one embodiment, coating layers 114and 116 are applied over at least 6 feet of the length of inner layer112, specifically over at least 8 feet of the length of inner layer 112,and more specifically over at least 10 feet of the length of inner layer112. In specific embodiments, these coating lengths are contiguouslengths of coating material.

In a specific embodiment, coating layers 114 and 116 are formed from anylon lacquer and have relatively smooth outer surfaces 118 and 120respectively. In at least some embodiments, it is believed that thenylon lacquer has a higher surface energy than a film or extruded layer,which leads to better bonding to the adhered polymer film. Compared tothe nylon extrusion, lacquer has a smoother surface. Different polymershave different surface energies, which can change bond strength, andwhen combined with surface roughness will provide different lowtemperature performance. To get an improved performance and a higherbond/peel force which can be achieved by matching glue to the layer onwhich it is being applied. Thickness and type of glue also relate topeel force. In the case of a pressure sensitive adhesive, the pressureat which film is applied is also a factor related to peel strength.

As shown in FIG. 3 , a tape blade film 122 is bonded or adhered to outersurface 120 of lower coating layer 116. In such embodiments and withoutbeing bound by theory, Applicant believes that placement of film 122 onthe lower surface provides reinforcement while at the same time reducesthe chance of delamination due to the mechanics of the tape blade duringwhipping. When film is applied to the bottom side, the film is undertension vs. compression during tape whip. This helps with increasedstiffness as well as low temperature performance of the film. In anotherembodiment, film 122 can be applied directly to the paint-print layerwithout a coating layer in between.

In general, tape blade film 122 is a reinforcing layer formed from apolymer material, and specifically a transparent polymer material toallow viewing of marking indicia located below film 122 in the tapeblade construction. In various embodiments, tape blade film 122 isformed from a polymer material having a high stiffness that Applicanthas determined reduces the likelihood of whip during tape bladeretraction. In various embodiments, the stiffness of film 122 isselected to be higher than other commonly used tape blade materials toreduce whipping. In a specific embodiment, tape blade film 122 is formedfrom a polyethylene terephthalate (PET) material, such as a PET materialhaving relatively high stiffness. In specific embodiments, tensilemodulus, flexural modulus and hardness will combine with thickness ofthe film to provide stiffness and when applied to tape, resists tapewhipping during retraction. FIG. 10 shows modulus and elongation atbreak data for materials that may be used for tape blade film 122. Inanother embodiment, tape blade film 122 is formed from a thermoplasticpolyurethane (TPU) material.

Tape blade film 122 is located adjacent to hook end 110 such that it isoverlapped by hook tab 124. Unlike coating layers 114 and 116, tapeblade film 122 has a length L1 such that tape blade film 122 extends arelatively short portion of the length of tape blade 14 from hook end110. In various embodiments, L1 is less than 20% of the total length oftape blade 14, specifically is less than 10% of the total length of tapeblade 14, and more specifically is 5% or less of the total length oftape blade 14. In various embodiments, L1 is 2 inches to 12 inches,specifically is 4 inches to 8 inches, and more specifically is 5 inchesto 7 inches. In a specific embodiment, L1 is 6 inches plus or minus 5%.Applicant has determined that a relatively short reinforcing layer suchas tape blade film 122 provides for improved tape blade strength, wear,crack and whip resistance without unduly increasing the total thicknessof the spooled tape blade.

In various embodiments, Applicant has determined that particularthicknesses of tape blade film 122 and of coating layers 114 and 116provide for increased tape blade protection without unduly increasingtape spool diameter. As shown in FIG. 3 , coating layer 114 hasthickness, T2, coating layer 116 has a thickness, T3, and tape bladefilm 122 has a thickness T4. In various embodiments, T4 is between 0.03mm and 0.3 mm, specifically is between 0.1 mm and 0.2 mm, and morespecifically is between 0.14 mm and 0.16 mm. In a specific embodiment,T4 is 0.15 mm plus or minus 0.005 mm. In another specific embodiment, T4is between 0.14 mm and 0.25 mm.

In various embodiments, coating layers 114 and/or 116 formed from apolymer material, such as a polymer lacquer, and have thicknesses T2and/or T3 between 0.01 mm and 0.03 mm and specifically is about 0.02 mm.In specific embodiments, coating layers 114 and/or 116 formed from anylon lacquer having thicknesses T2 and/or T3 between 0.01 mm and 0.03mm and specifically is about 0.02 mm. In a specific embodiment, steelthickness is 0.11, nylon lacquer is 0.02-0.03 thick on each side.

In specific embodiments, tape blade film 122 is adhered to the adjacentcoating layer via a layer of adhesive material 126. In variousembodiments, adhesive layer 126 is formed from a polymeric adhesive suchas a pressure sensitive adhesive. In a specific embodiment, adhesivelayer 126 is a pressure sensitive acrylic material.

Applicant has determined that by balancing the thickness of tape bladefilm 122 and the thickness of adhesive layer 126, a very high level ofadhesion of tape blade film 122 to tape blade 14 can be achieved. Invarious embodiments, the thickness of adhesive layer 126 is 0.01 mm and0.05 mm, specifically is 0.01 mm to 0.035, and more specifically is 0.02mm plus or minus 5%. In various embodiments, the ratio of the adhesivelayer thickness to T4 is selected to provide improved adhesion/peelstrength. In various embodiments, the ratio of the adhesive layerthickness to T4 is between 0.05 and 0.25, specifically is between 0.1and 0.15 and more specifically is between 0.13 and 0.14.

In specific embodiments, Applicant has determined that level of adhesionstrength (as determined by the peel strength test defined by ASTMD3330and described below) is substantially higher than commercially availabletape measures tested by Applicant. Applicant has determined that thismeasured property of a tape blade protective layer correlates with thelikelihood of delamination of the protective layer from the tape blade,which is one of the primary failure modes of a tape blade protectivelayer. In various embodiments, the peel strength between tape blade film122 and the adjacent coating layer is greater than 9 lbs., specificallyis greater than 10 lbs. and more specifically is greater than 11 lbs. Inspecific embodiments where coating layer 116 is a smooth layer of nylonlacquer, Applicant's designs achieve peel strengths greater than 18 lbs.(see e.g., examples in Table 1 below).

Referring to FIG. 4 , dimensional details of tape blade film 122 areshown according to an exemplary embodiment. In the specific embodimentshown, tape blade film 122 is sized for attachment to an inner metallayer 112 having a width of 32 mm.

Referring to FIGS. 3 and 4 , because of the positioning of tape bladefilm 122 adjacent hook assembly 26, hook rivets 128 pass through tapeblade film 122. To accommodate hook rivets 128, tape blade film 122includes at least one opening for each hook rivet 128. In the specificembodiment shown, hook assembly 26 includes two rivets 128, and thus,tape blade film 122 includes a first rivet opening 130 and a secondrivet opening 132. To position rivet openings 130 and 132 adjacent tohook assembly 26, rivet openings 130 and 132 are located in the firsthalf, and specifically the first quarter, of the length of tape bladefilm 122. In another embodiment, if PET film is applied before holepunching for rivets, film 122 and the other layers of the tape blade canbe stamped at same time.

Referring to FIG. 5 , multiple tape blade films 122 may be provided on aroll 140 of release liner 142. During manufacture of tape blade 14, onetape blade film 122 is removed from roll 140 and adhered via adhesive toeach tape blade. FIG. 6 shows a cross-sectional view of a particularembodiment of tape blade film 122 on the release liner 142. In variousembodiments, the thicknesses of tape blade film 122, adhesive layer 126and release liner 142 are shown in FIG. 6 . In one embodiment, thethickness dimensions shown in FIG. 5 are in inches, and in anotherembodiment, the thickness dimensions shown in FIG. 5 are in millimeters.

FIG. 7 shows hook end 150 according to an exemplary embodiment. Hook end150 is substantially the same as hook end 110, except for thedifferences discussed herein. In the arrangement of hook end 150, tapeblade film 122 is coupled to outer surface 118 of upper coating layer114. In this arrangement, tape blade film 122 is located on the uppersurface of tape blade 14, and is positioned such that an outer surfaceof tape blade film 122 is in contact with an inner surface of hook tab152.

Tape Blade Film and Adhesive Materials

In various embodiments, Applicant has identified a variety of specificmaterials for tape blade film 122 and adhesive layer 126 that arebelieved to improve one or more of the performance characteristics oftape blade film 122 discussed herein.

In specific embodiments, tape blade film 122 is formed from a PETmaterial. In general, Applicant has determined that the stiffer thematerial of tape blade film 122, the more resistance it provides to stoptape blade 14 from whipping during retraction. Applicant has determinedthat PET is an especially stiff film compared to other potentialpolymers, while still being transparent. In a specific embodiment, tapeblade film 122 is formed from PET film 75% CAS. NO. 931-36-2.

In a specific embodiment, tape blade film 122 is a PET film with acrylicglue forming layer 126. In this embodiment, the film with glue has 75%PET, 12.5% polyurethane, 10% epoxy resin, 2.5% curing agent.

In specific embodiments, tape blade film 122 is formed from a polymermaterial, such as PET, having the following physical characteristics.Transparent in color, density in g/m3 of 1.395-1.405; Melting Point,GB/T 13541, 259.5°; Tensile Strength, MPA, GB/T 13541, 170/210;Elongation at Break, %, GB/T 13541, 130/110; Heat Shrinkage, %, GB/T13541, 1.5/0.5); Continuous Use Temperature, −20° C.˜120° C.).

In various embodiments, the material that forms adhesive layer 126 is apressure sensitive polymer adhesive and specifically is a pressuresensitive acrylic material. In a specific embodiment, the material thatforms adhesive layer 126 is an acrylic glue that includes: polyurethane12.5% (CAS. NO. 51852-81-4), modified epoxy tree ester modified epoxyresin 10% (CAS. NO. 25068-38-6); curing agent 2.5% CAS No. 931-36-2.

In a specific embodiment, the material that forms adhesive layer 126includes one or more of the following properties: Initial adhesion,GF/INCH, FINAT 9, >1000; 180° Peel Strength, GF/INCH, ASTM D3330, >800;Permanent Adhesion, H, FINAT 8, >24; Thickness, ASTM D3652, (0.03±0.002)MM; Continuous Use Temperature, −10° C.˜80° C.

Peel Strength and Test Procedure

As noted above, Applicant has determined that peel strength of tapeblade film 122 formed as discussed herein has much higher peel strengthas compared to commercially available prior art tape measures. Withoutwishing to be bound by theory, Applicant believes that the tape bladefilms discussed herein have increased peel strength due to the nature ofthe interface between the adjacent coating layer and the adhesive. Inaddition, the thickness of the tape blade film also appears to relate topeel strength.

Table 1 below shows the peel strength of two arrangements of tape blade14 with tape blade film 122 discussed herein compared to twocommercially available tape measures. The procedure for testing peelstrength is set forth in ASTMD3330, and images of an example testprocedure are shown in FIGS. 8 and 9 . As shown in FIG. 8 , Instronclamp 200 grips the film on tape blade 202, and Instron clamp 204secures the tape blade. For setup, the tape blade is located so that thefolded over area of the film is within Instron clamp 200. A one inchlength of test sample tape blade 202 is clamped within Instron clamp204, and the base is located six inches from the edge. FIG. 9 shows theclamping of the sample. The clamp is lowered so that the clamp can gripthe fold over section, and the machine's extension is set to zero. Inthe test, the extension rate is set to 8 mm/s. Start is selected to runthe test, and when the clamps have reached the maximum extension, returnto zero is selected. The output data from the test run is machineextension distance and force, and the force measurements withindifferent regions are averaged such as within a region of 75.0 mm to225.00 mm.

TABLE 1 Blade Film Average Width Blade Film Material Location ForceAverage Test Sample (mm) Coating and Thickness Glue Top/Bottom (lb) (lb)Prototype 1 32 Nylon 0.15 mm PET 0.02 mm Pressure Top 19.32 19.04Lacquer Sensitive Acrylic Glue 18.77 19.02 Prototype 2 32 Nylon 0.15 mmPET 0.02 mm Pressure Bottom 19.83 18.73 Lacquer Sensitive Acrylic Glue18.13 18.22 Commercially 32 Polyester 0.14 mm .047 pressure sensitiveTop  8.67  8.59 Available Prior thermoplastic Acrylic glue  8.57 Art 1Polyurethane  8.53 (TPU) Commercially 32 Polyester 0.13 mm TPU 0.047 mmPressure Top  7.07  6.77 Available Prior sensitive Acrylic glue  7.23Art 2  6.01

Commercially Available Prior Art 1 and Commercially Available Prior Art2 each have a blade that has a first film over the entire blade, and asecond film at the first six inches that is overtop the first film.Commercially Available Prior Art 1 has thicker films than theCommercially Available Prior Art 2. For reference, labeled and annotatedmagnified photographs of Commercially Available Prior Art 1 andCommercially Available Prior Art 2 are shown in FIGS. 11 and 12 ,respectively

In addition to the peel strength testing discussed above, Applicant alsotested the number of retractions of various tape blade that it took tocause delamination of the various tape blade protective layers. Duringthis testing, Applicant took 10 samples of the 25 ft. version ofCommercially Available Prior Art 2 tape measures and performedretraction tests. During this test, the tape is pulled out of thehousing by 8′ and then the tape measure retracts the tape back into thehousing. This is performed on a testing machine that holds each tapemeasure in the same position for each test and minimizes humanvariation. The Commercially Available Prior Art 2 tape measures took, onaverage, 0.75 seconds to retract the 8′ (range of 0.66-1.0 seconds) andaveraged 162.4 cycles before the tape blade tore (range of 56-314cycles). In addition, Applicant took 10 new samples of the 25 ft.version of Commercially Available Prior Art 2 tape measures, removed theprotective film located on the first 6 inches or so, and performed thesame retraction test. The Commercially Available Prior Art 2 without thefilm averaged 0.739 seconds to retract (range of 0.65-0.99 seconds) andaveraged only 58.9 cycles before the blade tore (range of 14-111). Thus,for Commercially Available Prior Art 2 tape measures tested, the film onthe first six inches increased the life by an average of 103.5 cycles.

Applicant also performed the same retraction tests with the 25 ft.versions Commercially Available Prior Art 1 tape measures (e.g., with 10samples with the film and 10 samples without the film). With the film,Commercially Available Prior Art 1 tape measures averaged 0.698 secondsto retract (range of 0.63-0.79 seconds) and averaged 179.7 cycles beforethe tape blade tore (range of 22-683). Without the film, CommerciallyAvailable Prior Art 1 tape measures averaged 0.685 seconds to retract(range of 0.60-0.76 seconds) and averaged 75.8 cycles before the tapeblade tore (range of 21-194 cycles). Thus, for Commercially AvailablePrior Art 1 tape measures, the film on the first six inches increasedthe life by an average of 103.9 cycles.

Applicant also performed the same retraction tests with the 25 ft.versions of Prototype 2. Applicant used a 25 ft. version of Prototype 2.Applicant tested three samples of Prototype 2 without the PET film onthe first six inches, which had an average retraction time of 0.83seconds (range of 0.83-0.84 seconds) and averaged 112 cycles before thetape tore (range of 65-173 cycles). Applicant then tested four samplesof Prototype 2 that did have the PET film on the first six inches of thetape blade, and these had an average retraction time of 0.86 seconds(range of 0.83-0.87 seconds) but averaged 2,023.8 cycles before the tapeblade tore (range of 1430-2331). Thus, the reinforcement of PET film onthe tape blade of Prototype 2 increased the life of the blade in thistest by over 1,911 cycles (i.e., lengthened the life by a factor of 18).

It should be understood that the figures illustrate the exemplaryembodiments in detail, and it should be understood that the presentapplication is not limited to the details or methodology set forth inthe description or illustrated in the figures. It should also beunderstood that the terminology is for description purposes only andshould not be regarded as limiting.

Further modifications and alternative embodiments of various aspects ofthe invention will be apparent to those skilled in the art in view ofthis description. Accordingly, this description is to be construed asillustrative only. The construction and arrangements, shown in thevarious exemplary embodiments, are illustrative only. Although only afew embodiments have been described in detail in this disclosure, manymodifications are possible (e.g., variations in sizes, dimensions,structures, shapes and proportions of the various elements, values ofparameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter described herein. Someelements shown as integrally formed may be constructed of multiple partsor elements, the position of elements may be reversed or otherwisevaried, and the nature or number of discrete elements or positions maybe altered or varied. The order or sequence of any process, logicalalgorithm, or method steps may be varied or re-sequenced according toalternative embodiments. Other substitutions, modifications, changes andomissions may also be made in the design, operating conditions andarrangement of the various exemplary embodiments without departing fromthe scope of the present invention.

Unless otherwise expressly stated, it is in no way intended that anymethod set forth herein be construed as requiring that its steps beperformed in a specific order. Accordingly, where a method claim doesnot actually recite an order to be followed by its steps or it is nototherwise specifically stated in the claims or descriptions that thesteps are to be limited to a specific order, it is in no way intendedthat any particular order be inferred. In addition, as used herein, thearticle “a” is intended to include one or more component or element, andis not intended to be construed as meaning only one. As used herein,“rigidly coupled” refers to two components being coupled in a mannersuch that the components move together in a fixed positionalrelationship when acted upon by a force.

Various embodiments of the invention relate to any combination of any ofthe features, and any such combination of features may be claimed inthis or future applications. Any of the features, elements or componentsof any of the exemplary embodiments discussed above may be utilizedalone or in combination with any of the features, elements or componentsof any of the other embodiments discussed above.

What is claimed is:
 1. A tape measure comprising: a housing: a reelrotatably mounted within the housing; an elongate blade wound around thereel, the elongate blade having an inner end coupled to the reel and anouter end extending out of the housing; a hook assembly coupled to theouter end of the elongate blade; and a retraction system coupled to thereel, wherein the retraction system drives rewinding of the elongateblade on to the reel; wherein the elongate blade comprises: an elongatemetal core having an upper surface and a lower surface, wherein theupper surface includes a concave curved section and the lower surfaceincludes a convex curved section; an upper polymer coating layercovering at least a portion of the upper surface of the elongate metalcore; a lower polymer coating layer covering at least a portion of thelower surface of the elongate metal core; an ink layer forming a seriesof measurement markings and located between the upper surface of theelongate metal core and the upper polymer coating layer; and aprotective film coupled via an adhesive to an outer surface of the lowerpolymer coating layer adjacent to the outer end of the elongate blade,the protective film having a length that is less than 20% of a totallength of the elongate blade; wherein the protective film has an averagethickness between 0.14 mm and 0.25 mm; wherein the adhesive has athickness between 0.01 mm and 0.05 mm, wherein a peel strength betweenthe protective film and the outer surface of the lower polymer coatingis greater than 9 lbs.
 2. The tape measure of claim 1, wherein thelength of the protective film is 2 to 12 inches.
 3. The tape measure ofclaim 1, wherein the hook assembly includes a hook tab that overlaps aportion of the protective film.
 4. The tape measure of claim 1, whereinthe protective film comprises a transparent PET material.
 5. The tapemeasure of claim 4, wherein the elongate metal core comprises a steelmaterial having a hardness of 45-60 RHC, the upper and lower polymercoating layers comprise nylon.
 6. The tape measure of claim 5, whereinthe upper and lower polymer coating layers comprise a nylon lacquerhaving a thickness between 0.01 mm and 0.03 mm.
 7. The tape measure ofclaim 1, wherein the elongate blade has a length less than 50 feet.
 8. Atape measure comprising: a housing: a reel rotatably mounted within thehousing; an elongate blade wound around the reel, the elongate bladehaving an inner end coupled to the reel and an outer end; a hookassembly coupled to the outer end of the elongate blade; and aretraction system coupled to the reel, wherein the retraction systemdrives rewinding of the elongate blade on to the reel; wherein theelongate blade comprises: an elongate metal core having an upper surfaceand a lower surface, wherein the upper surface includes a concave curvedsection and the lower surface includes a convex curved section; and aprotective film coupled via an adhesive to the elongate metal core, theprotective film having a length less than a total length of the elongateblade, wherein a peel strength between the protective film and anadjacent surface of the elongate blade is greater than 9 lbs.
 9. Thetape measure of claim 8, further comprising a polymer coating layercoupled to the elongate metal core, wherein the protective film isdirectly coupled to an outer surface of the polymer coating layer viathe adhesive.
 10. The tape measure of claim 9, wherein the length of theprotective film is less than a length of the polymer coating layer. 11.The tape measure of claim 10, wherein the polymer coating layer iscoupled to a lower surface of the elongate metal core, and theprotective film is located underneath the elongate metal core.
 12. Thetape measure of claim 8, wherein the peel strength is measured via thetest defined by ASTMD3330.
 13. A tape measure comprising: a housing: areel rotatably mounted within the housing; an elongate blade woundaround the reel, the elongate blade having an inner end coupled to thereel and an outer end; a hook assembly coupled to the outer end of theelongate blade; and a retraction system coupled to the reel, wherein theretraction system drives rewinding of the elongate blade on to the reel;wherein the elongate blade comprises: an elongate metal core having anupper surface and a lower surface, wherein the upper surface includes aconcave curved section and the lower surface includes a convex curvedsection; an upper nylon coating layer covering at least a portion of theupper surface of the elongate metal core; a lower nylon coating layercovering at least a portion of the lower surface of the elongate metalcore; an ink layer forming a series of measurement markings and locatedbetween the upper surface of the elongate metal core and the upper nylonlayer; a pressure-sensitive adhesive layer coupled to at least one of anouter surface of the upper nylon coating layer and an outer surface ofthe lower nylon coating layer, wherein the pressure-sensitive adhesivelayer has a thickness of between 0.01 mm and 0.05 mm; and a protectivefilm coupled to the pressure-sensitive adhesive layer adjacent to theouter end of the elongate blade.
 14. The tape measure of claim 13, theprotective film has a length that is less than 20% of a total length ofthe elongate blade.
 15. The tape measure of claim 14, wherein thepressure-sensitive adhesive layer is coupled to an outer surface of thelower nylon coating layer.
 16. The tape measure of claim 13, wherein theupper and lower nylon coating layers each comprise a nylon lacquerhaving a thickness between 0.01 mm and 0.03 mm.
 17. The tape measure ofclaim 13, wherein the elongate blade has a length less than 50 feet. 18.The tape measure of claim 13, wherein a peel strength between theprotective film and the at least one of the outer surface of the uppernylon coating layer and the outer surface of the lower nylon coatinglayer is greater than 9 lbs.